Ten years of fast neutron therapy in Münster.

The indication for neutron therapy in the treatment of malignant tumors is often uncertain. We therefore would like to present our experience of neutron therapy for different tumors in different localizations and discuss the indications for radiotherapy with neutrons. In Münster, 269 patients were treated with neutrons between 1985 and 1995, via a deuterium-tritium generator with an energy of 14 MeV. The tumors, treated mainly with neutrons, were 64 adenoid cystic carcinomas of the salivary glands, 42 soft tissue sarcomas, 37 rectal cancer recurrences and 20 recurrences in the head and neck region. Furthermore, patients with non adenoid cystic carcinomas of the salivary glands as well as ten other tumor sites also received this treatment, mainly with palliative intent. The 64 patients with adenoid cystic salivary gland tumors had either an unresectable primary tumor, an unresectable recurrence or residual tumor (R1, R2) after surgery. These patients showed complete remission in 78% and partial remission in 22%. The 2-year survival rate was 76%. Forty-two patients with soft tissue sarcomas after resection (R1, R2) and different gradings had an overall survival rate after 5 years of 53%. The 37 patients with rectal cancer recurrence experienced rapid pain relief in nearly 90% of cases. In agreement with the results in the literature, there seems to be an indication for neutron therapy in cases of unresectable primaries, unresectable recurrences or residual tumor after surgery in adenoid cystic carcinomas. Results regarding soft tissue sarcoma treatment with neutrons seem to show superiority in comparison with photon therapy. The treatment with neutrons of rectal recurrences has a very good palliative effect. The radiotherapy treatment with neutrons in all the other tumors did not demonstrate any proven superiority in comparison with photon radiation.